1. Field of the Invention
The present invention also relates to the art of producing speech suitable for speech recognition from input speech.
The present invention further relates to the art of extracting necessary information from input speech.
The present invention, in addition, relates to the art of processing speech mixed with noise.
2. Description of the Related Art
An interactive system for inputting information based on the recognition of speech uttered by a user and carrying out a process corresponding to the contents of the input information, e.g., outputting a response speech, has been proposed.
Also, in consideration of input speech being spoken in a noise environment, it has been thought to improve the detection rate of user speaking zones or the speech recognition rate by using noise data.
General methods of acquiring noise data are discussed below.
(1) A method of preparing several speech input devices includes placing one of the speech input devices near the user""s mouth and the others at places remote from the user""s mouth, and acquiring user speech and noise by the separate input devices at the same time.
(2) A method of preparing a noise training mode includes inhibiting the user from speaking, and taking in only noise before the user speaks.
The method (1) is advantageous in acquiring noise data in real time, but the user cannot use a plurality of speech input devices at the same time in many cases. In particular, personal computers that have become increasingly common these days each have only on microphone terminal, and therefore a system employing the method (1) has a difficulty in finding widespread use. The method (2) has the disadvantage that if sudden or peculiar noise is taken in during the noise training mode, noise data different from that produced in the actual environment is stored, and therefore all results of subsequent speech recognition are affected. Also, if noise taken in during the noise training mode differs from actual noise, the results of speech recognition are adversely affected. In addition, a noise training step requires redundant work for the user.
With the view of solving the above-stated problems in the related art, the present invention intends to realize speech recognition adaptively dealing with surrounding noise even when only one speech input device is employed.
Also, the present invention intends to realize speech recognition adaptively dealing with surrounding noise without a tiresome training work.